U.S. patent application number 15/514606 was filed with the patent office on 2017-08-10 for top plate for cooking device.
The applicant listed for this patent is Nippon Electric Glass Co., Ltd.. Invention is credited to Toshimasa KANAI, Yusuke YAMAZAKI.
Application Number | 20170227234 15/514606 |
Document ID | / |
Family ID | 55746447 |
Filed Date | 2017-08-10 |
United States Patent
Application |
20170227234 |
Kind Code |
A1 |
YAMAZAKI; Yusuke ; et
al. |
August 10, 2017 |
TOP PLATE FOR COOKING DEVICE
Abstract
Provided is a top plate for a cooking device including a glass
sheet (2) and a light-shielding film (3) formed on a lower surface
(2c) of the glass sheet (2) through sputtering. The light-shielding
film (3) contains an oxide, a nitride, or an oxynitride of a
transition metal of Group 6 to Group 11 on the periodic table. In
this manner, a color close to grey can be achieved as a color of
the light-shielding film (3) while insulating properties of the
light-shielding film (3) are secured.
Inventors: |
YAMAZAKI; Yusuke; (Shiga,
JP) ; KANAI; Toshimasa; (Shiga, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Nippon Electric Glass Co., Ltd. |
Shiga |
|
JP |
|
|
Family ID: |
55746447 |
Appl. No.: |
15/514606 |
Filed: |
September 1, 2015 |
PCT Filed: |
September 1, 2015 |
PCT NO: |
PCT/JP2015/074821 |
371 Date: |
March 27, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C03C 2217/281 20130101;
C03C 2218/156 20130101; C03C 17/245 20130101; F21V 33/0044
20130101; F21V 3/061 20180201; F24C 15/10 20130101; C03C 17/3411
20130101; C03C 2217/213 20130101; G06F 3/041 20130101; C03C 17/28
20130101; C03C 2217/217 20130101; C03C 2217/219 20130101; C03C
17/22 20130101; H05B 6/12 20130101; F21V 11/00 20130101; F21Y
2113/13 20160801; C03C 17/3482 20130101; F21Y 2115/10 20160801 |
International
Class: |
F24C 15/10 20060101
F24C015/10; C03C 17/245 20060101 C03C017/245; G06F 3/041 20060101
G06F003/041; F21V 3/04 20060101 F21V003/04; F21V 11/00 20060101
F21V011/00; C03C 17/22 20060101 C03C017/22; F21V 33/00 20060101
F21V033/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 17, 2014 |
JP |
2014-212280 |
Claims
1. A top plate for a cooking device, comprising: a glass sheet; and
a light-shielding film formed on one surface of the glass sheet
through sputtering, wherein the light-shielding film contains an
oxide, a nitride, or an oxynitride of a transition metal of Group 6
to Group 11 on a periodic table.
2. The top plate for a cooking device according to claim 1, wherein
the light-shielding film contains an oxynitride of Cu or Cr.
3. The top plate for a cooking device according to claim 2, wherein
transmissivity to light having a wavelength of from 400 nm to 700
nm is in a range of from 3% to 43%.
4. The top plate for a cooking device according to claim 1, wherein
the light-shielding film contains SiO.sub.2, and CuO or CoO and is
formed by laminating a first layer having a content of CuO or CoO
set from 0.01% to 30% by mass and a second layer made of Si.
5. The top plate for a cooking device according to claim 1, wherein
the light-shielding film contains two or more kinds of metal oxides
selected from the group consisting of CoO, NiO, Fe.sub.2O.sub.3,
MoO.sub.6, MnO.sub.2, and Cr.sub.2O.sub.3, and SiO.sub.2 in which a
content of the metal oxides is set to 0.01% to 60% by mass.
6. The top plate for a cooking device according to claim 1, wherein
the light-shielding film has a value of an electrical resistance of
3 k.OMEGA./.quadrature. or larger.
7. The top plate for a cooking device according to claim 1, wherein
a value obtained by dividing a maximum value of transmissivity to
light having a wavelength of from 400 nm to 700 nm by a minimum
value thereof is 4.0 or smaller.
8. The top plate for a cooking device according to claim 1, further
comprising: a touch sensor arranged on a side opposite to the glass
sheet through the light-shielding film therebetween; and a
light-emitting diode configured to emit light to be transmitted
through the light-shielding film.
Description
TECHNICAL FIELD
[0001] The present invention relates to a top plate for a cooing
device, comprising a glass sheet and a light-shielding film formed
on the glass sheet.
BACKGROUND ART
[0002] As a top plate for a cooking device such as an
electromagnetic heating cooking device, an infrared heating cooking
device, or a gas cooking device, there exists a top plate including
a glass sheet. On the glass sheet, a light-shielding film made of a
metal, e.g., Ti is formed. The light-shielding film visually
shields a heater or the like arranged inside the cooking device,
thereby providing good appearance to the cooking device.
[0003] In recent years, a top plate including a touch panel having
a surface of the glass sheet as a touch surface has been
manufactured for the purpose of improving convenience of the
cooking device. This kind of top plate requires enhanced insulating
properties by reducing electrical conductivity of the
light-shielding film formed on the glass. Therefore, a
light-shielding film made of a semiconductor is formed on the glass
sheet in some cases in place of the light-shielding film made of a
metal.
[0004] An example of such a top plate is disclosed in Patent
Literature 1. In the top plate for a cooking device disclosed in
Patent Literature 1, a light-shielding film made of Si being a
semiconductor is formed on the glass sheet. As a result, as
compared to the light-shielding film made of a metal, the
insulating properties can be enhanced.
CITATION LIST
Patent Literature
[0005] Patent Literature: JP 2009-139055 A
SUMMARY OF INVENTION
Technical Problem
[0006] However, the top plate for a cooking device disclosed in
Patent Literature 1 has the following problem. Specifically, the
light-shielding film made of Si has low transmissivity to light
having a short wavelength and has high transmissivity to light
having a long wavelength in a visible light region. This property
makes the light-shielding film made of Si be liable to have a color
close to red (for example, reddish brown).
[0007] For the top plate for a cooking device, there are demands
for use of various colors other than red (for example, achromatic
colors (such as grey)) as the color of the light-shielding film.
With the above-mentioned light-shielding film made of Si, the
insulating properties can be enhanced. However, in actuality, it
has been impossible to achieve the requested color.
[0008] The present invention, which has been made in view of the
above-mentioned circumstances, has a technical object to achieve
various colors other than red as a color of a top plate for a
cooking device comprising a glass sheet and a light-shielding film
formed on the glass sheet, while securing insulating properties of
the light-shielding film.
SOLUTION TO PROBLEM
[0009] According to one embodiment of the present invention, which
has been devised to achieve the above-mentioned object, there is
provided a top plate for a cooking device, comprising: a glass
sheet; and a light-shielding film formed on one surface of the
glass sheet through sputtering, wherein the light-shielding film
contains an oxide, a nitride, or an oxynitride of a transition
metal of Group 6 to Group 11 on a periodic table.
[0010] By turning the transition metals of Group 6 to Group 11 on
the periodic table into the oxides, the nitrides, or the
oxynitrides, various colors other than red can be achieved as a
color thereof. Therefore, various colors other than red (for
example, monochromatic colors (such as grey)) can be achieved as a
color of the light-shielding film containing the oxide, the
nitride, or the oxynitride of those transition metals. Further, the
light-shielding film has a large electrical resistance, and hence
insulating properties can be secured.
[0011] It is preferred that the light-shielding film contain an
oxynitride of Cu or Cr.
[0012] When the light-shielding film containing the oxynitride of
Cu is used as the light-shielding film, the insulating properties
can be further improved while various colors other than red (color
close to grey) are achieved as the color thereof. Further, when the
light-shielding film containing the oxynitride of Cr is used as the
light shielding film, the color can be made closer to grey while
the insulating properties are secured. Specifically, when the
insulating properties of the light-shielding film are prior to the
color of the light-shielding film, it is suitable to use the
light-shielding film containing the oxynitride of Cu. When the
color of the light-shielding film is prior to the insulating
properties of the light-shielding film, it is suitable to use the
light-shielding film containing the oxynitride of Cr.
[0013] For the above-mentioned top plate for a cooking device, it
is preferred that transmissivity to light having a wavelength of
from 400 nm to 700 nm be in a range of from 3% to 43%.
[0014] In this manner, the transmissivity is reduced in the range
of the wavelength of from 400 nm to 700 nm. Therefore, the
light-shielding film becomes more suitable to visually shield an
inside of the cooking device. Further, a fluctuation range of the
transmissivity can also be reduced in the range of the wavelength
of from 400 nm to 700 nm. As a result, when light emitted from a
light-emitting diode is to be transmitted through the top plate for
a cooking device, the emitted light is more easily transmitted
uniformly therethrough regardless of the color of the light emitted
from the light-emitting diode.
[0015] The above-mentioned light-shielding film may contain
SiO.sub.2, and CuO or CoO and may be formed by laminating a first
layer having a content of CuO or CoO set from 0.01% to 30% by mass
and a second layer made of Si.
[0016] The first layer has high transmissivity to light having a
short wavelength and has low transmissivity to light having a long
wavelength in a visible light region. Therefore, the first layer is
likely to have a color close to blue. Further, the second layer has
low transmissivity to the light having the short wavelength and has
high transmissivity to the light having the long wavelength in the
visible light region. Therefore, the second layer is likely to have
a color close to red. In this manner, when the light-shielding film
is formed by laminating the first layer and the second layer, the
color thereof can be made close to grey. Further, according to the
light-shielding film, the insulating properties can be secured.
Still further, with the light-shielding film, the transmissivity
can be extremely reduced in the visible light region. Therefore,
the light-shielding film becomes more suitable to visually shield
the inside of the cooking device.
[0017] The above-mentioned light-shielding film may contain two or
more kinds of metal oxides selected from the group consisting of
CoO, NiO, Fe.sub.2O.sub.3, MoO.sub.6, MnO.sub.2, and
Cr.sub.2O.sub.3, and SiO.sub.2 in which a content of the metal
oxides is set to 0.01% to 60% by mass.
[0018] Even with the light-shielding film described above, various
colors other than red can be achieved as the color thereof while
the insulating properties of the light-shielding film are
secured.
[0019] It is preferred that the above-mentioned light-shielding
film have a value of an electrical resistance of 3
k.OMEGA./.quadrature. or larger.
[0020] In this manner, the value of the electrical resistance of
the light-shielding film becomes sufficiently larger. Thus, the
insulating properties can be further improved.
[0021] It is preferred that, for the above-mentioned top plate for
a cooking device, a value obtained by dividing a maximum value of
transmissivity to light having a wavelength of from 400 nm to 700
nm by a minimum value thereof be 4.0 or smaller.
[0022] In this manner, the fluctuation range of the transmissivity
can be extremely reduced in the range of the wavelength of from 400
nm to 700 nm. Therefore, when the light beams emitted from the
light-emitting diodes are transmitted through the top plate for a
cooking device, the emitted light beams can be uniformly
transmitted therethrough regardless of the colors of the light
beams emitted from the light-emitting diodes.
[0023] The above-mentioned top plate for a cooking device may
comprise: a touch sensor arranged on a side opposite to the glass
sheet through the light-shielding film therebetween; and a
light-emitting diode configured to emit light to be transmitted
through the light-shielding film.
ADVANTAGEOUS EFFECTS OF INVENTION
[0024] As described above, according to the present invention, it
is possible to achieve various colors other than red as a color of
the top plate for a cooking device comprising the glass sheet and
the light-shielding film formed on the one surface of the glass
sheet while insulating properties of the light-shielding film are
secured.
BRIEF DESCRIPTION OF DRAWINGS
[0025] FIG. 1 is a plan view for illustrating a top plate for a
cooking device according to a first embodiment of the present
invention.
[0026] FIG. 2 is a vertical sectional front view for illustrating
the vicinity of a touch panel part in the top plate for a cooking
device according to the first embodiment of the present
invention.
[0027] FIG. 3 is a vertical sectional front view for illustrating
the vicinity of a touch panel part in a top plate for a cooking
device according to a third embodiment of the present
invention.
DESCRIPTION OF EMBODIMENTS
[0028] A top plate for a cooking device according to embodiments of
the present invention is described with reference to the
accompanying drawings.
First Embodiment
[0029] First, a configuration of a top plate for a cooking device
according to a first embodiment of the present invention is
described.
[0030] FIG. 1 is a plan view for illustrating a top plate 1 for a
cooking device according to the first embodiment. As illustrated
FIG. 1, the top plate 1 for a cooking device includes a single
glass sheet 2 made of transparent crystallized glass having a
transmissivity of 75% or higher to light having a wavelength of
from 400 nm to 700 nm. The glass sheet 2 includes cooking parts 2a
for cooking with a pan or the like placed on the glass sheet 2 and
a touch panel part 2b including a touch panel configured to control
temperature of a cooking device.
[0031] FIG. 2 is a vertical sectional front view for illustrating
the vicinity of the touch panel part 2b. As illustrated in FIG. 2,
a light-shielding film 3 is formed on a lower surface 2c (surface
on a side opposite to a surface on which the pot or the like is
placed) of the glass sheet 2 through sputtering. The
light-shielding film 3 is a film containing an oxide, a nitride, or
an oxynitride of a transition metal of Group 6 to Group 11 on the
periodic table.
[0032] In this embodiment, the light-shielding film 3 is made of an
oxynitride of Cu being the transition metal of Group 11 on the
periodic table. As a modified example, the light-shielding film 3
maybe made of an oxynitride of Cr being the transition metal of
Group 6 on the periodic table. Even in this case, the
light-shielding film 3 is formed on the lower surface 2c of the
glass sheet 2 through sputtering. The light-shielding film 3 may be
formed entirely on the lower surface 2c of the glass sheet 2 or
only on a region that can shield at least a heater or the like
arranged inside the cooking device.
[0033] On a side opposite to the glass sheet 2 through the
light-shielding film 3 therebetween (below the light-shielding film
3), a touch sensor 4 configured to detect contact of a human body
(finger) with the touch panel is arranged. Further, a
light-emitting device 5 configured to emit light beams L to be
transmitted through the light-emitting film 3 to illuminate the
touch panel is arranged below the touch sensor 4. The
light-emitting device 5 includes a plurality of light-emitting
diodes configured to emit the light beams L of different colors
(for example, blue, yellow, green, red, and the like).
[0034] For the top plate 1 for a cooking device, transmissivity to
the light beams L, each having a wavelength of from 400 nm to 700
nm, is set in a range of from 3% to 43%. A magnitude of the
transmissivity can be regulated by, for example, changing a
composition or a thickness of the light-shielding film 3. Further,
a value of an electrical resistance (sheet resistance) is set to 3
k.OMEGA./.quadrature. or larger. A magnitude of the value of the
electrical resistance can be regulated by, for example, changing
the composition or the thickness of the light-shielding film 3
formed through sputtering. In addition, in this embodiment, a value
obtained by dividing a maximum value of the transmissivity of the
top plate 1 for a cooking device to the light having the wavelength
of from 400 nm to 700 nm by a minimum value thereof is set to 4.0
or smaller. Further, it is preferred to set reflectance of the top
plate 1 for a cooking device to 10% or smaller, more preferably, to
5% or smaller.
[0035] Operations and effects of the above-mentioned top plate for
a cooking device according to the first embodiment are
described.
[0036] According to the top plate 1 for a cooking device according
to the first embodiment, various colors other than red can be
achieved as a color of the light-shielding film 3. Further, the
light-shielding film 3 has the value of the electrical resistance
of 3 k.OMEGA./.quadrature. or larger, and hence insulating
properties can be secured.
[0037] When the light-shielding film 3 made of the oxynitride of Cu
is used as the light-shielding film 3, the insulating properties
can be further improved while various colors other than red (color
close to grey) are achieved as the color. Meanwhile, when the
light-shielding film 3 made of the oxynitride of Cr is used as the
light-shielding film 3, the color can be made closer to grey while
the insulating properties are secured.
[0038] In the top plate 1 for a cooking device comprising the
light-shielding film 3, the value of the transmissivity is reduced
to be as low as 3% to 43% in the range of the wavelength of from
400 nm to 700 nm. Therefore, the light-shielding film 3 becomes
more suitable to visually shield an inside of the cooking device.
Further, a fluctuation range of the transmissivity can be reduced
in the range of the wavelength of from 400 nm to 700 nm. As a
result, the light beams L emitted from the light-emitting diodes
can be uniformly transmitted regardless of the colors of the
emitted light beams from the light-emitting diodes.
Examples
[0039] As Examples of the present invention, a light-shielding film
was formed on a glass sheet through sputtering to manufacture a top
plate for a cooking device. Then, for items (1) to (3),
specifically, (1) the color of the formed light-shielding film, (2)
the transmissivity of the top plate for a cooking device to light
having the wavelength of from 400 nm to 700 nm, and (3) the value
of the electrical resistance of the light-shielding film were
examined. This examination was carried out for a top plate for a
cooking device comprising a light-shielding film made of an
oxynitride of Cu (Example 1) and a top plate for a cooking device
comprising a light-shielding film made of an oxynitride of Cr
(Example 2).
[0040] Specific conditions of the formation of the light-shielding
film on the glass sheet are described.
[0041] For the sputtering, a magnetron sputtering apparatus was
used. Further, as targets, a target made of Cu was used in Example
1, and a target made of Cr was used in Example 2. Still further,
crystallized glass having a thickness of 4 mm, which is
manufactured by Nippon Electric Glass Co. Ltd. (product name:
N--O), was used as the glass sheet.
[0042] Then, the target and the glass sheet were arranged inside a
chamber so that the target and the glass sheet were opposed to each
other. Then, the sputtering (reactive sputtering) was performed
while causing O.sub.2 and N.sub.2 in addition to Ar to flow into
the chamber.
[0043] In Example 1, a ratio of Ar, O.sub.2, and N.sub.2 to flow
into the chamber was set to Ar:O.sub.2:N.sub.2=83.3:11.1:5.6. In
Example 2, the ratio was set to Ar:O.sub.2:N.sub.2=0:50:50. In
addition, the light-shielding film in Example 1 was formed so as to
have a thickness of 130 nm. The light-shielding film in Example 2
was formed so as to have a thickness of 15 nm.
[0044] As conditions common to Example 1 and Example 2, an
atmosphere was adjusted so that a degree of vacuum in the chamber
became from 2.0.times.10.sup.-1 Pa to 6.0.times.10.sup.-1 Pa.
Further, a range of a voltage to be applied was set from 3 kW to 30
kW.
[0045] A specific method of examining the above-mentioned items (1)
to (3) is described.
[0046] (1) The color of the light-shielding film was checked
visually. (2) For the transmissivity of the top plate for a cooking
device, a maximum value and a minimum value of the transmissivity
(incident angle 0.degree.) to the light having the wavelength of
from 400 nm to 700 nm were determined through use of a
spectrophotometer manufactured by Hitachi, Ltd. (product name:
U-4100). (3) For the value of the electrical value of the
light-shielding film, the value of the electrical resistance (sheet
resistance) was determined through use of Loresta MP manufactured
by Mitsubishi Chemical Corporation.
[0047] Results of the examinations for the above-mentioned items
(1) to (3) are described.
[0048] In Example 1, (1) the color of the light-shielding film was
close to grey. (2) The maximum value of the transmissivity of the
top plate for a cooking device was 41.7%, and the minimum value
thereof was 4.1%. (3) The value of the electrical resistance of the
light-shielding film was 1.4.times.10.sup.5
k.OMEGA./.quadrature..
[0049] In Example 2, (1) the color of the light-shielding film was
close to grey. (2) The maximum value of the transmissivity of the
top plate for a cooking device was 13.3%, and the minimum value
thereof was 7.1%. (3) The value of the electrical resistance of the
light-shielding film was 3.2 k.OMEGA./.quadrature..
[0050] As described above, it is understood from the results of
examinations that the color closer to grey was obtained as the
color of the light-shielding film in both of Example 1 and Example
2. Further, it is understood that a variation range of the
transmissivity of the top plate for a cooking device is reduced in
the range of the wavelength of from 400 nm to 700 nm in both of
Example 1 and Example 2. Further, it is understood that the
sufficient value of the electrical value for securing the
insulating properties of the light-shielding film was obtained in
both of Example 1 and Example 2.
Second Embodiment
[0051] A top plate for a cooking device according to a second
embodiment of the present invention is described. In the second
embodiment and a third embodiment described below, the items that
have already been described in the first embodiment are denoted by
the same reference symbols in the drawings referred to in the
second embodiment and the third embodiment. Thus, the overlapping
description is omitted, and only differences from the first
embodiment are described.
[0052] The top plate 1 for a cooking device according to the second
embodiment differs from the above-mentioned top plate 1 for a
cooking device according to the first embodiment in that the kind
of light-shielding film 3 formed on the lower surface 2c of the
glass sheet 2 is different.
[0053] In the second embodiment, the light-shielding film 3
contains two or more kinds of metal oxides selected from the group
consisting of CoO, NiO, Fe.sub.2O.sub.3,MoO.sub.6,MnO.sub.2, and
Cr.sub.2O.sub.3, and SiO.sub.2 in which a content of the metal
oxides is set to 0.01% to 60% by mass. As one modified example, the
light-shielding film 3 may contain SiO.sub.2, NiO, and CoO in which
a content (total content) of NiO and CoO is set to 0.01% to 60% by
mass. Further, as another modified example, the light-shielding
film 3 may contain SiO.sub.2, NiO, CoO, and Fe.sub.2O.sub.3 in
which a content (total content) of NiO, CoO, and Fe.sub.2O.sub.3 is
set to 0.01% to 60% by mass. The light-shielding film 3 is formed
on the glass sheet 2 through sputtering as in the first embodiment
described above.
[0054] Even with the top plate 1 for a cooking device according to
the second embodiment, various colors other than red can be
achieved as the color of the light-shielding film 3. The
light-shielding film 3 is increased in electrical resistance, and
hence the insulating properties can be secured.
Third Embodiment
[0055] A top plate for a cooking device according to the third
embodiment of the present invention is described.
[0056] FIG. 3 is a vertical sectional front view for illustrating
the vicinity of the touch panel part 2b in the top plate 1 for a
cooking device according to the third embodiment. As illustrated in
FIG. 3, the top plate 1 for a cooking device according to the third
embodiment differs from the above-mentioned top plate 1 for a
cooking device according to the first embodiment in that the kind
of light-shielding film 3 formed on the lower surface 2c of the
glass sheet 2 is different and in that the light-shielding film 3
is formed by laminating a first layer 3a and a second layer 3b.
[0057] In the third embodiment, the light-shielding film 3 is
formed by laminating the first layer 3a containing SiO.sub.2 and
CuO in which a content of CuO is set from 0.01% to 30% by mass and
the second layer 3b made of Si. As a modified example, the first
layer 3a may contain SiO.sub.2 and CoO in which a content of CoO is
set from 0.01% to 30% by mass. Further, in the top plate 1 for a
cooking device, a value obtained by dividing the maximum value of
the transmissivity to the light having the wavelength of from 400
nm to 700 nm by the minimum value thereof is set to 4.0 or smaller.
A magnitude of the transmissivity of the top plate 1 for a cooking
device to the light beams L, each having the wavelength of from 400
nm to 700 nm, can be regulated by changing compositions or
thicknesses of the first layer 3a and the second layer 3b. It is
preferred that the value obtained by dividing the maximum value of
the transmissivity by the minimum value be set to 2.5 or smaller,
more preferably, 2.0 or smaller.
[0058] Further, in this embodiment, the first layer 3a is directly
formed on the glass sheet 2, and the second layer 3b is further
formed on the first layer 3a. The first layer 3a is formed on the
glass sheet 2 through sputtering. Then, after the first layer 3a is
formed on the glass sheet 2, the second layer 3b is formed on the
first layer 3a through sputtering. As a modified example, the
second layer 3b may be directly formed on the glass sheet 2, and
the first layer 3a may be formed on the second layer 3b.
[0059] Here, the first layer 3a has high transmissivity to light
having a short wavelength and has low transmissivity to light
having a long wavelength in the visible light region. Thus, the
first layer 3a has a color close to blue. Further, the the second
layer 3b has low transmissivity to the light having the short
wavelength and has high transmissivity to the light having the long
wavelength in the visible light region. Thus, the second layer 3b
has a color close to red.
[0060] Even with the top plate 1 for a cooking device according to
the third embodiment, the light-shielding film 3 may have a color
close to grey. Further, the light-shielding film 3 is increased in
electrical resistance, and hence the insulating properties can be
secured. Further, according to the top plate 1 for a cooking device
of the third embodiment, the following operations and effects can
also be obtained.
[0061] In the top plate 1 for a cooking device comprising the
light-shielding film 3, the value of the transmissivity can be
extremely reduced in the visible light region. With this, the
light-shielding film 3 is more suitable to visually shield the
inside of the cooking device. Further, in the top plate 1 for a
cooking device, the variation range of the transmissivity is also
extremely reduced in the range of the wavelength of from 400 nm to
700 nm. Therefore, the emitted light beams L can be uniformly
transmitted regardless of the colors of the light beams emitted
from the light-emitting diodes.
[0062] Here, the top plate for a cooking device according to the
present invention is not limited to the configurations described
with the above-mentioned embodiments. For example, the
light-emitting film may have a configuration other than the
configurations described in the embodiments. Another configuration
may be employed as long as the film contains the oxide, the
nitride, or the oxynitride of the transition metal of Group 6 to
Group 11 on the periodic table.
Reference Signs List
[0063] 1 top plate for cooking device [0064] 2 glass sheet [0065]
2a cooking part [0066] 2b touch panel part [0067] 2c lower surface
[0068] 3 light-shielding film [0069] 3a first layer [0070] 3b
second layer [0071] 4 touch sensor [0072] 5 light-emitting device
[0073] L light beam
* * * * *